1. Field of the Invention
This invention relates to shipping racks, and more particularly, to a rack for shipping and/or storing glass sheets and the like, which can be readily assembled and disassembled, i.e., collapsed.
2. Discussion of the Prior Art and Technical Problems
Shipping bins or racks that are readily assembled and disassembled are desirable. This is because more empty racks can be stored in a given area if the racks can be disassembled, thereby more efficiently utilizing storage area. Further, more empty racks can be returned in a truck or railcar if the racks can be disassembled, thereby reducing tansportation costs.
However, in order to realize any economical advantage from savings in storage space and transportation costs, (1) the racks should be readily assembled and disassembled, (2) the loaded racks should provide adequate protection to the glass sheets during handling and/or shipping of the loaded rack, and (3) the loaded rack should be easily accessible for lifting as for example by a forklift truck.
The racks should be readily assembled and disassembled because of high labor costs which can offset any savings realized in reduced storage space or reduced transportation costs. The racks when loaded with glass sheets should adequately protect the glass sheets because damaged glass sheets can reduce savings realized in reduced storage space or reduced transportation costs. The loaded racks should be easily accessible for lifting because increased handling to position the rack for lifting, e.g., by a forklift truck can reduce savings realized in reduced storage space and reduced transportation costs.
Disclosed in U.S. Pat. No. 3,709,358 is a package of glass sheets. The package includes a stack of glass sheets arranged vertically on a pair of spaced L-shaped brackets. The stack of glass sheets is strapped to the L-shaped brackets.
Although the package of glass sheets as disclosed in the above-mentioned patent is readily assembled and disassembled, it has limitations. More particularly, (1) the package of glass sheets does not provide adequate protection to the glass during handling and/or shipping of the package; and (2) the package can only be lifted as by a forklift truck from the front or back side.
The package of glass disclosed in the above-mentioned patent does not provide adequate protection to the glass sheets during handling and shipping because the L-shaped supports are not maintained in an upright position and in spaced relation during loading, unloading and shipment thereof. In the instance when the sheets are individually loaded or unloaded, the L-shaped members can rack, i.e., pivot toward or away from each other. When this occurs, the glass sheets can fall from the L-shaped members and become damaged. Further, there are no provisions for protecting the edges of the glass sheets during shipment and handling. For example, there are no facilities to prevent a forklift truck from engaging and chipping the edges of the loaded glass sheets. The package of glass disclosed in the above-identified patent is normally lifted as by a forklift truck from the front or back sides by engaging the bottom of the stack of glass sheets. This has several drawbacks. Namely, padding has to be provided on the forks of the forklift truck to prevent damage to the bottom edge of the glass sheets; and the package has to be positioned so that the forklift truck has access to either the front or back side of the package of glass.
Another drawback of the package of glass as disclosed in the above-mentioned patent is that straps, e.g., 5 straps, are used to prevent longitudinal and lateral motion of the glass sheets during shipment. This practice is expensive because of material costs and labor costs to apply the straps to the stack of glass sheets. Further, disposing of the straps creates a solid waste problem.
Still further, the jointure of the pair of arms to provide the L-shaped support does not have additional supporting structure to prevent the arms from separating due to transportational forces. The transportation forces increase as the height of the loaded glass pack increases. Therefore the rack of the above-identified patent may be suitable for shipping small glass plates but not for shipping large glass plates.
In U.S. Pat. No. 3,645,389, there is taught a device for packaging a stack or stacks of glass sheets. The device includes a rectangular frame formed of two wooden L-shaped sections and is positioned around a stack of glass sheets. A panel or floor member is disposed between one side of the frame and a face of the stack so that the edges of the glass sheets rest upon the floor member. On both ends of the floor member there are mounted stops which abut faces of the stack to prevent movement of the stack with respect to the frame.
The drawbacks of the above-identified packing device is lack of versatility in shipping different quantities and sizes of glass sheets. More particularly, the L-shaped sections encompass the glass sheets thereby requiring that the L-shaped section be tailor made to prevent movement of the glass sheets during shipment. Although fillers can be used to secure the sheets within the L-shaped supports, disposing of the fillers creates a solid waste disposal problem.
Further, the packing device lacks structural stability because the device can rack during shipment or handling or stacking. This is because the transportation forces tend to shift the packing device from a rectangular shaped packing device to a parallelogram shaped packing device. When this occurs, forces are put on the vertical members that can cause them to fail or the pack of glass sheets to become unstable. The instability of the glass sheets becomes more critical when the racks are stacked because the stacked racks can topple.